Integrated Crop Management News

Links to these articles are strongly encouraged. Articles may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If articles are used in any other manner, permission from the author is required.

Yellow Corn, Wet Soils and N Loss - Part 1

June 20, 2008
Image of experimental plot for wet soil and nitrogen loss experiments

By John Sawyer, Department of Agronomy


Yellow Corn


As many are well aware, the wet conditions this spring have resulted in tremendous corn coloration and growth variation across fields. In my travels to the ISU research farms west of Ames this week for research work, it is clear that corn is recovering and beginning rapid growth, but that growth is very uneven and varies on a quite small scale.


Weed Science Field Book Available

June 19, 2008

Despite the cancellation of the Iowa State University Weed Science field day originally scheduled for June 26, there is still an opportunity to review the weed management demonstrations and research at the ISU Curtiss Farm on South State Street in Ames. 

Since planting and herbicide applications are still underway, particularly for soybeans, it is suggested that a good opportunity to see the weed science research exists after the first week in July. 

Assessing Private Well Safety After Flooding

June 19, 2008

By Tom Glanville, Department of Agricultural and Biosystems Engineering

As the floodwater recede, we are getting lots of questions from rural residents wanting to know if their wells are safe to use. Here are three of the most common questions.

There was no flood water on my property, but the nearby fields and road were flooded. How do I know if my well should be tested. 

The Nation’s Wet Spot

June 14, 2008
Map of the US showing the percent of normal precipitation

By Elwynn Taylor, Department of Agronomy


It only takes a glance at the year’s (water year begins in October) precipitation map to identify the region of ABNORMAL wetness. The record setting floods of 2008 are no surprise in light of the records. If it seems that high water years in the Midwest are increasingly common since about 1970; they are.



Hayfield Lodging – Management Concerns and Guidelines

June 13, 2008

By Stephen K. Barnhart, Department of Agronomy and Mark Hanna, Department of Agricultural and Biosystems Engineering  

Rain, wind, hail, and unavoidable harvest delays have led to lodged and flat hayfields across the state. This is not usually a concern in more normal seasons, but if it occurs, producers have to manage for and around it.  

A ‘bright side’ of delayed harvest is that the forage plants have longer to accumulate carbohydrate ‘stores’ and maintain plant vigor. 

Measuring the Nitrogen Status

June 12, 2008
Image of N-deficient corn and well-fertilized, non-N limiting strips

This year the corn growth is behind, and with the wet soils some fields will be sampled later than normal. Late sampling may complicate test interpretation.

Managing Manure Storage Structures During Wet Weather

June 12, 2008

By Robert Burns, Department of Ag and Biosystem Engineering 

During excessively high rainfall periods Iowa producers with open manure storages should closely monitor manure levels to prevent these structures from over-topping.

Estimating Nitrogen Losses

June 11, 2008

By John Sawyer, Department of Agronomy

One method to judge nitrogen (N) loss is to calculate an estimate. Predicting the exact amount is quite difficult as many factors affect losses. However, estimates can provide guidance for supplemental N applications.

Nitrogen Loss – How Does it Happen?

June 10, 2008

By John Sawyer, Department of Agronomy

Much of Iowa is experiencing excessively wet conditions this spring. With the continued large rainfalls and flooding conditions, nitrogen (N) loss is an issue. While the wet period early this spring had an influence on N in the soil, excessively wet conditions now are especially critical for N losses due to warm soils and considerable conversion of applied fertilizer and manure N to nitrate.

Pages